CA2247015A1 - Readily replaceable roll covers - Google Patents

Abstract

A textile pull roll cover (20) is disclosed which has a plurality of surface stems (28) projecting outwardly from one side thereof. The surface stems are uniformly shaped and disposed on the pull roll cover, and the surface stems collectively define an operative contact surface for a textile web. A
plurality of hooking stems (55) project from an opposite side of the pull roll cover. The hooking stems are adapted to releasably affix the pull roll cover to a cylindrical pull roll having loop structure material (45) adhered thereto. A method for making a textile pull roll is disclosed, as well as a method for changing the outer textile engaging surface of a textile pull roll using the hook-and-loop opposed fastening arrangement, with the loop material being disposed on the outer cylindrical surface of the pull roll. Also disclosed is a textile pull roll cover which has an exterior side (251) with desired frictional characteristics for engagement with an advancing textile web. On its opposite side, the pull roll cover is affixed to a cylindrical outer surface of a textile pull roll by a repositionable pressure sensitive adhesive disposed therebetween. A method for making a textile pull roll is disclosed, as well as a method for changing a pull roll cover using repositionable pressure sensitive adhesive.

Description

CA 0224701~ 1998-08-20 W~ 97/3280S PCT/US97/01704 READlLY REPLACEABLE ROLL CO~ERS

BACKGROUND OF THE INVENTION
The present invention relates to apparatus for selective çngAg~.ment with an advancing web. ln particular, the invention relates most specifically to apparatus and methods for the assembly and ready replacement of covers for rolls used to engage advancing webs.
It is well known to provide a cylindrical roll with specifically desired frictional lU characteristics on its exterior surface for use in web advancement and lleal,~lel~L
processes. In the textile industly, tlle use of rolls to convey, pull and hold back fabric is very common, and these rolls are referred to as pull rolls. For in~t~nt~e, weavin~
machines. inspection machines, finishil1g lines, napping lines, sueding lines and dye lines all contain numelous pull rolls to aid in pert'orming such operations. Steel or aluminllm 1~ rolls themselv,es do not pro~ide surfaces witll sufficient frictional forces to keep fabric from slipping in most applications. Such rolls are thus covered or coated with a material whicll aids in gently guidillg tlle fabric through the textile processing m~f hin-?ry without distorting its weave, yet keeping the fabric relatively uniform in advancement and spread.
The cover Oll a pull roll may have a low or high coefflcient of friction, depending upon the particular tàbric, process cllaMcteristics and desired engagement or traverse of the pull roll with the fabric. Nul1lel0us materials have been used to define the frictional interaction betweell tl~e roll sulfàce and the fabric. Typical prior art pull roll cover materials include cork~ rubber, modified cork, smooth rubber. sandpaper and bristle-bearing materials. During use of such materials, their frictional characteristics can change. For installce, CO11~ and mbber-based materials tend to glaze over as they wear and become smoother, presentill=, a cllall~e in fi-iction level to the fabric web over time.
This can result in a slow deterioration of fabric quality or increased motor power usage due to slippin~,, whicll are both difFicult to detect. In addition, abrasives such as 3() sandpaper do not wear evenly, because of theil- random surface textures. Further, while abrasives such as sandpaper presellt higller frictional characteristics for a pull roll cover, CA 0224701~ 1998-08-20 W 097/32805 PCT~US97/01704 they are non-unifoml by desi~n and thus are ~Inc \it~ble for some fabric webs because their non-uniformity results in damage to the fabric. Pull roll covers based on a bristled stnucture (SUCIl as the BRUSHI,O~TM bnush material of Minnesota Mining and ManufactLIring Company. St. Paul, Minnesota), are also random in bristle dispersion and alignment.
A pull roll cover material is typically applied by helically wrapping a 5 to 7.5 cm ~two to three inch) ~vide strip of the material down the length of the roll. Adhesion of the material to the roll surface has been accomplished by the use of contact cements, spray adhesives, and nonrepositionable pressure sensitive adhesives. To remove such 1() roll covers from a roll requires removal ofthe roll from the textile processing m~f~.hin~ry, and in some installces the machining off' of the covering. These types of adhesion arranoen1ellts typically lead to build-ups of adhesive on the roll surface over time, contain flamlllable solvents in the adhesive, re~luire long cure times on the roll surface, and in many cases require the use of flammable solvents for roll clean-up.
Environmental concerns and restrictions no~ prohibit the use of many of these adhesives in textile plants, thereby requiring the removal and application of roll surfaces by outside parties and at locations other thall the textile processinO tàcility.One type of pull roll cover folms a cylindrical brush~ as disclosed in Dupre U.S.
Patent 4,627,1'~7. il1 ~upre, a fabric strip containinO bristles on an outer peripheral surtàce thereof is ~vrapped in a lleli~; about a cylinder. The fabric strip is adhered to the cylinder by means of an adhesive such as polyurethane. ThrouOh use, the bristles wear do~n and the r enlailling covering must be replaced. To remove such a covering bonded to the cylinder by an adhesive requires the use of solvents. This can be messy, relatively time consumin~ (res~ltin~g in machine dowlltime) and, as mentioned above, the use of solvents to remove adhesives creates undesirable hazardous waste removal issues.In an e~'olt to address these environlllenta3 concerns. and also to forrn a morereadil!~ replaceable pull roll cover, mecllallical tàstenino schernes (such as hook-and-loop ~stener stmctures) have been used instead of adhesives to bond the cover material to the roll. One roll cover material curTently available for this purpose has 3mm (1/8") trim .~) nyloll 6, 12 bristle BRUSHL,ONT"I brusll material (available from Minnesota ~Linin~ and ManLIfacturillO Compally, St. Paul, l~linnesota) 011 one side of a support substrate, with CA 022470l~ l998-08-20 a loop structure material on its other side. A hook structure material (having projecting hooks or capped stems thereon) is bonded to tlle exterior surface of the cylindrical roll, typically in strip fornl wrapped thereabout in a helix. The bristle/loop structure assembly is also wrapped in Stlip form itl a helix about the cylindrical roll, with the loop structure interengaging with the hook structure to affix the bristle/loop structure assembly to the pull roll cylinder. While this arranoement allows for ready removal ofthe exterior bristle bearing fabric, and replacement thereof with an alternative roll exterior material having a loop stmcture backing, it also is not ideal. The combination of the bristles, support substrate and hool;-and-loop fastener form a pull roll cover assembly having a relatively o higll profile. Fulthel, if the pull roll cover material is wrapped in an imperfect helix along the roll, one or more hooks may be inadvertently exposed from the hook structure material mounted on the cylindlical roll. These exposed hooks can damage the fabric web being traversed by the roll by picl;ing or tearing at fabric fibers, creasing the fabric, scuffing its surface or by causing some other similar surface phenomenon.
A typical textile pull roll ~,vill have a diameter in the ran~e of 10 to 30 cm (4-12 incl1es~, but can be smaller or largel-. A higll profile ~relatively thick) pull roll cover increases the effective diameter of a pull roll, and this effect is even more significant on a smaller diameter pull roll e.g., a 2.5 - 7.~ cm (1-3 inch~ diameter pull roll. It is an undesh-able necessity that drive roll speeds be adjusted if a significant change in roll diameter results from the application of a roll cover, and thus a pull roll cover should be as thin as possible.
The pich-up or transfel- of paniculates or fluids by a pull roll cover is also undesirable. A cover material is aiso unacceptable if it allows lint and fiber build-up thereoll during use. In addition, in some applications the roll or fabric web will be wet.

2~ For example, a roll cover must not pick up and hold fabric dyes from the m~ f~ctl~ring process. ~olor cl1anges are commoll and the transfer of dves from one fabric lot to anotller is ~Inacceptable.
In view of the disadvantages associated with the various pull roll cover schemesof the prior an, it is desirable to pro~,ide a pull roll that has a changeable exterior 3() covering. wllerein the coverin, is relatively inexpensive, reusable or replaceable, easily and securely attachable to the c~lindrical pull roll and which, in use, does not allow CA 0224701~ 1998-08-20 W O 97/3280S PCT~US97/01704 undesirable contact or dama;,e to tlle web traversed thereby. Other desirable features in a replaceable pull roll cover are that tlle cover assembly have a relatively low profile, that it not collect lint or fibers~ and that it not transfer dyes between webs. In addition, an exterior material for a pull roll cover is desired that has a long life, and provides the desired frictional characteristics, or range of frictional characteristics for customer fle~ibility.

SIJMMARY OF THE INVENTION
In one embodiment, the present invention includes an en~,agement apparatus for selective enga~emellt with an advancill~ web. The engagement apparatus inc.llldçs a base having an outer surface with hooli-ellgagin~, structures disposed thereon, and a surface substrate sheet havin;, first and second major surfaces. The second surface of the substrate sheet has desired charactelistics for frictional engagement with an advancing web. A plurality of llool;in~ stems are provided on and project from the first 1~ surface ofthe substlate sheet. The hool;in~ stems include means for hooking the hool~-engagin~ surfaces on tlle outer surface of the base to releasably affix the surface substrate to the base.
ln anothel embodilllellt the presellt invention includes a low profile ensga,~Pmtont apparatus for use 011 a roll ha~ill;, a cylindrical outer surface. The engagement apparatus 2() comprises a surface substl-ate sheet havin~ first and second sides, with the second side thereof havin~, desired characteristics for fi-ictional enga~ement with an advancing web.
A repositionable press~ll-e sensitive adllesive is disposed between the cylindrical outer surface of the roll and the first side of tlle surfàce substrate sheet to releasably adhere the surface substrate slleet to tlle cylindrical outer surface of the roll for re~ cem~nt or 2:. reali,gnment.
In anotller embodiment, the second surface includes means for defining a frictional enga~en1ent sulface for the advancin~ web. The defining means inclu(lçs a plurality of surface stems prc jectin~ outwardly from the second surface of the surface substrate sheet, witll the surface stems collectively definin<J an operative contact surface .~() for contactin~ the advanci~ web. Preferably, the surface stems are disposed in a CA 0224701~ 1998-08-20 WO 97/32805 PCT~'US97~01704 selected arrangement on and formed integrally with the second surface of the surface substrate sheet.
The present invention further includes a method of making a textile pull roll, wllich includes prov;din(J a base having an outer cylindrical surface, and providing a :, substrate sheet havin~ first and second major sides. The first side of the substrate sheet is releasably bonded to the outer cylindrical surface of the base. A plurality of surface stems are provided on and project outwardly from the second side of the substrate sheet, witll the sulface stems being formed integrally with the surface substrate and having outer ends which are generally uniform in height. The surface stems collectively defme o an operative textile contact surface for contacting a textile web. The bonding of the substrate sheet to the outer cylindrical sulface of the base includes adhering the first side of the substrate sheet to the outer cylindricai surface by opposed hook-and-loopfasteners, with the ioop fasteners bein;, on the outer cylindrical surface of the textile pull roll.
s The present inventioll also includes a further method of making a ro~l, which includes providing a base havin~r an outer cylindrical surface and providing a substl-ate sileet havillg first and second major sides. The second side of the substrate sheet has the desired characteristics for frictional engagement with an advancing web.
The metllod furthel includes releasably bonding tlle first side ofthe substrate sheet to the 2() outer cylindrical surface of the base with a repositionable pressure sensitive adhesive to permit read~ removal or realigllment of the substrate sheet relative to the base.
Preferably~ tlle inventive method furthel includes positioning the repositionable pressure sensitive adhesive on the first side of the substrate sheet prior to the bonding thereof to the base.
2:) The invention is further embodied in a method of changing the outer textile en~,a~in~r surface of a textile pull roll. In this process, a pull roll is provided having a cylindlical pull roll base, a loop fastener structure secured to the pull roll base, and an initial suTbstrate sheet releasably affixed to the loop fastener structure. The initial substrate sheet has first and second majc-r sides, with the second side of the substrate 3() sheet being defined by a te.~tile engagemellt material and the first side thereof being defined by a hoo~ fastenel- stluctul-e WlliCIl iS releasably engaged witll the loop fastener CA 0224701~ 1998-08-20 W O 97/32805 PCT~US97/01704 stl~lcture on the pull roll base. Tl~e initial substrate sheet and textile engagement material thereon are removed from the pull roll base by ~lir~nQg;~ginl7, the hook fastener structure on the initial substrate sheet from the loop fastener structure on the pull roll base. A replacement substrate sheet having frst and second major sides is provided, Witll its second side being defined by a replacement textile engagement material and its first side beinjg defined by a hoo3~ fastener structure. The replacement substrate sheet is affixed to the pull roll base by adherillg the hook fastener structure thereon to the loop fastener structure on the pull r oll base.
In another embodiment of the above process, a pull roll is provided having a 0 cylindrical pull roll base, with an initial substrate sheet releasably affixed to the pull roll base. The initial substrate sheet has first and second major sides, with the second side of the initial substrate sheet being defined by a textile enga~ement material and the first side thereof being bonded to the pull r oll base by a repositiollable pressure sensitive adhesive.
The initial substMte sheet and textile engagemellt material thereon are removed from the pull roll base by overcoming the adherence force ofthe repositionable pressure sensitive adhesive. A replacement substrate sheet havillg first and second major sides is provided, witll its second side being defined by a replacement textile engagement material. The replacement substrate sheet is affixed to the cylindrical pull roll base by means of a repositionable pressure sensitive adhesive disposed therebetween to perrnit repl~c.o.m.ont 2n or realio,nmellt thereof on tlle cylindrical pull roll base.

BRIEF DESCRIPTION OF THE DRAWINGS
The present invelltion will be further explained with reference to the drawing figures refèrenced below, whereill like structure is referred to by like numerals 2~ througllout the several views.
FIG. I is an isometric view of a textile web being advanced over a pull roll cover of the present invention.
FIG. '~A is a top plan view of one prefèl-red embodiment of the exterior pull roll cover of the present invention having upwardly projecting surface stems.
3() FIG. 2B is a sectional vie~i as talien along, lines 2B--2B in FIG. 2A.

CA 022470l~ l998-08-20 W O 97/32805 PCTfiUS97~01704 FIG. 3 is a scl1en1atic illustration of an apparatus and process for forrning the pull roll cover of FTGS. 2A and '7B.
FIG. 4 is a schematic view of a strip of loop fastener structure partially woundabout the cylindrical base of a pull roll.
FIG. 5 is a scl1e~l~atic view of a strip of pull roll exterior cover material partially wound over tl1e f rst strip and cylindrical base of a pull roll.
~IG. 6 is a sectional view as taken along lines 6-6 in FIG. 5.
FIG. 7 is a sectional view of an alternative pull roll cover assembly.
FIG. ~ is a sectional view of an altemative pull roll cover assembly.
() FIG. 9 is a schematic view of a strip of another preferred embodiment of a pull roll exterior cover matelial paltially woul1d about the cylindrical base of a pull roll.
FIG. 10 is a sectional view as taken along lines 10-10 in FIG. 9.
FIG. ] I is an enlar~ed sectional view of a portion of FIG. 10.
FIG. 12 is a sectional view of an alternate pull roll cover of the present invention.
While the above-identified dra~ing figures set forth several pl e~l, ~d embodiments, other embodiments of the present invention are also contemplated, as noted in the discussiol1. This disclosure presel1ts illustrative embodiments of the present invel1tiol1 by way of replesel1tatiol1 and not limitation. Numerous other modifications and embodimel1ts can be devised by those skilled in the art which fall within the scope and spirit of the principles of this invelltiol1. The drawing figures have not been drawn to scale as it has been necessary to enlarge celtain portions for clarity.

DETAILED DESCRII'TIOI\' OF THE PREFERRED EMBODlMENTS
~5FIG. I illustrates a te~ctile or fabric web 10 being processed along a web travel path whicll is defined, at least in palt, by te.~;tile pull rolls such as pull rolls 12, 14 and 16.
Such rolls may be driven or idler rollers, depending UpOIl the processing application.
The sulfaces of the IOIIS are coated or covered with materials having the desired frictional cllal acteristics t'or the application and for the fabric web being processed. The 3()pull rolls are intended to l;eep the fablic web taut and uniformly disposed as it is processed. Dependil-~ upon the re(1uirements for a specific pull roll, a high degree of CA 0224701~ 1998-08-20 friction may be required bet~een the pull roll and fabric web to prevent slippage, or a lo~v degree of friction may be required to allow a controlled degree of slippage of the fabric ~eb over the pull roll FIGS 2A and 2B illustrate the inventive pull roll cover material of the present invention ~unctionally, the inventive pull roll cover 20 has a substrate 22 with a first side 2a. adapted to be moul1ted OI1tO a pull roll, and a second side 26 defining a frictional engagemeIlt surlàce f'or a fabric web which may be traversed or advanced over the pull roll This engagemel1t surtàce is furtl1er de~lned by a plurality of surface stems 28, which are disposed in a selected alTangement ~it is preferred that this arr~n~Pment be a 1() predetermined pattern) across the second surface 26, and are formed to have a generally uniform height projection from the substrate sheet 22 The selected arr~ng~ment for surlàce sten~ dispersal is prefèrably a unifol m an-ay, althou;,h any arrangement of surface stems is possible (includil1g even a randomly designed dispersal of surface stems within a ~iven area~ In a prefèrred embodiment, the surface stems 28 are arrayed in staggered 1~ rows across the substMte 22, SUCII as row a, b, c, d in FIG 2 Preferably, each surface stem 28 projects at a light al~,le relative to the second side 26 of the substrate 22, but altemati~ely an,,led stem olientations are also contemplated Preferably, the surface stems 2~ and substrate ~ are formed integrally as a stemweb, and the substrate requil-es no additional support layer or backing material As ~) shown, the surface stems 28 of the pretèrred embodiment are equally spaced apart and eacll is row1d in lateral cross section, having a generally uniform diameter along its height, from its outer end 30 to the second side 26 The surface stems 28 collectively serve to defil1e an operative region or contact surface for the pull rol? cover which contacts the advancil1~, fabric web 2~ With a pull roll cover material 20 of this design (e g, FIGS 2A and 2B), the surface sten-s 28 provide a very unifol-m fi-ictional engaging surface for presentation to the ad~ancil1g fabric web, both initially, and as the surface stems '~8 wear down during usage The surface stems ~ ~vear unifolmly, and since the diameter of the surfacestems 2~ is ~enerally uniform alon~ their height in the pret'erred embodiment, the surface area of sten~ ends 30 does not change because of changing stem structure along the entire heioht of tlle sulface stems 2~ as the sllrface stems 28 wear down The inventive CA 0224701~ 1998-08-20 W ~97/3280~ PC~AUS97~704 pull roll co~er material thus presents a frictional engaCSing surtàce that is resistant to 1azing and maintaills a constallt friction level during its use~l life.
The use of uni~orn~ly disposed and formed surface stems as the ~nCSzl~rin~ surface of a pull roll cover results in a highly controllable and predictable frictional ~.n~m~nt s relationship between the pull roll cover and web. In addition to opposed roll and web material-to-material frictional interenga~ement characteristics, the precisely formed nature of the pull roll cover surface intl-od~lces a significant mech~nic~l engagement component into the fi-ictional en~,agement relationship. The upstanding surface stems on the pull roll cover penetrate interstices on the web surface (e.g., between the crossed ] (~ fibers of its weave for a woven web) to engage the web mechanically. Testing sll~e~t~
that such surface stems disposed on a pull roll cover do not damage many woven fabrics, as other~vise might be e~cpected. Outer end portions of the surface stems actually en~ra~re tlle tl-reads of a ~oven fàbric web to mechanically engage with the wovell web as it is advanced past the pull rol~. While such mechanical interengagement ~5 is a factor in the fi-ictional relafiollship of prior art pull roll cover rnaterials and woven webs (e.g., bristle based covers or abrasive material covers), those cover materials are not entirely uniform in the dispersement of their bristles or abrasive particles (as well as being less than fully uniform in terms of the size, height and diameter of their bristles or palticles). As a r esult, the web en(~agement surfaces presented by those prior art cover 2~) materials to the web ~vere not as unitorlll t'rictionally as desired. The uniforrnly shaped, sized and disposed surfàce stems of the present invelltive pull roll cover present a homogelleous fi-ictional surt'ace f'or contactin~, the web. The surface stems of the in~entive pull roll cover are particularly useful and effective in this regard when the web has a relatively ulliform sulface structure (e.g., woven or knitted3, ~Itho~l~h the 2~ mechallical en~,a,,elllellt characteristics are evident in relation to other web structures as well (e.~r..Spllll bonded. nollwoven~ etc.3.
The inve1ltive pull roll cover 20 illustl-Ated in FIGS. 2A and 2B is ,~s;sLallL to the piCI;Lip of lint and fiber dL!rill;, use. Fulther, it is possible to use materials to fabricate the inventive pull roll cover 20 so that the cover 20 is resistant to dye pickup and transfer from the fabric web. In one embodimellt, the inventive pull roll cover 20 is molded ~om SRD7-:-60 impact copolymer resin available fi-om Sliell Polypropylene Company, CA 022470l5 l998-08-20 W O 97132805 PCT~US97/01704 Houston, Texas. Other possible materia]s for forming the pull roll cover 20 include PrevailT''' 3050, available from Dow Chemical Company, Midland, Michigan, HimontKSOS4P, Montell-Himont, Atlanta, Georgia, and HytrelT~'~ 5526 or SurlynrM 1702, both available from E. 1. du Pont de Nemours & Co., Inc., Wilmington, Delaware.
The nature of the inventive cover 20 is described by its co~ Jdlion of stem height, stem diameter, stem spacing and number of stems per square inch. The frictional characteristics of the cover 20 presented to the fabric web are altered by changing stem density, stem diameter. stem height or stem spacing, which in tun1 affect the surface area presented by the stem ends 30 of the surface stems 28 to the fabric web, and also affect the mechal1ical engagemellt relationsl1ip between the weave of the fabric web and the surface stems Z8 (e.;,., a chan3e in stem height may affect stem flexibility). Four examples of these parameters for the cover 20 are listed in Table T below:

TABLE l l:~
Stem Density Substrate Stem Height Stem Stem ltem Thickness Diameter Spacing 0.127 mn1 Approx. 0.4 mm 1.4 mm Al stemslcm2 0.94 mm 50 stems/cn12 0.1~7 mm Approx. 0.38 mm 1.4 mm A'~ 0.64 mm 150 stems/cn1~ 0.1 tmn Approx. 0.13 mm to 0.8 mm A3 0.15mm 0.18mm 355 sten1s/cn1~ 0.076 mm Approx. 0.13 mm to 0.53 mm A4 0.15 mm 0.18 mm The stem spacin(J is the distance between centers of two adjacent stems. As shown in FIG. ~A, in a preferred embodiment the stems are uniformly spaced apart in all directions across the second sulface '~6 of the substrate ''''.
The paMmeters listed in Table l are not meant to be limitil1g, and numerous variations in those paralneters are possible ~'or a particular cover. For instance, the stem density is preferably greater thall ]7 stems/cm~, and more preferably greater than 15 stems/cm~. Table l presents specific stern density examples of 50, 150 and 355 stems/cm~. but stem web slem densities greater than 355 stems/cm2 are also possible.

I ~

_ CA 0224701~ 1998-08-20 WO 97~32805 PCT~US97/01704 Further, the surface stems may have a heigllt gradient across the pull roll (e.g., shorter in center tltan near its ends~ in order to facilitate web handling, the stems may not be round in cross-sectioll, and the stem density and/or stem spacin~ may vary across the pull roll.
In some applications, it may even be desirable that adjacent stems have dirre~ heights, or to have stems which change in profile (i.e., cross-section) along their height (e.g., a cylindrical stem having an enlarged, tapercd stem base~.
In the pull r oll cover 20 just desclibed, and the methods of mal~ng such pull roll cover materials described below, the cover material is typically formed by molding a flo~vable material. The flowable material can be any suitable material, such as a 1() polymer, a metal or a ceramic precursor. It is also within the scope of this invention to use t~vo or more din'elel-L flou~able materials to make the surface stems. The flowable material is a foamed or solid polymeric material (such as that described above), such as a themloplastic material or a thel-lllosettill, malerial. Othel- suitable materials include thennoplastic polyul-etllalles, polyvinyl clllolides, polyamides, polyimides, polyolefins 1~ (e.g., polyethylelle and polypropylene), polyesters (e.,~., polvethylene terephthalate), polystyrelles. nylons, acetals, block polymers (e ~, polystyrene materials ~ith elastomeric segments, availal~le from Shell Chemical Company of Houston, Texas, under the designation KratollT'''), polycarbonates, thermoplastic elastomers, and copolymers and blends thereot' The flowable material may also contain additives 2n includill~J but not limited to fillers, t;bers, antistatic agents, lubricallts, wetting agents, foamin~ agents~ sultàctallts, piglllellts~ dyes, coupling agents, plasticizers, suspending agrellts and the lil;e.
FIG. 3 illustrates one embodiment of an apparatus and process for forming the inventive pull roll cover. This process gellerally involves molding surface stems in a 2:, substrate sheet fi-om whicll the surface stems project. Substrate sheet 22 is formed, bearin;, a plul-ality of projecting surtàce stems 2~ on one majc)r surface thereof. The moldin(r step may include any suitable moldill~, apparatus~ as kno~vn in the molding art.
For example, tlle surfàce stems and substrate sheet could be injection molded, molded by compressill;, a heated sheet nlelllbel- agaillst a molding surface, or molded by mol-iing 3() a flowable material over and into the cavities of a mold, which may be stationary or movin;, (e.g., a belt~ a tape Ol a drum).

CA 0224701~ 1998-08-20 W O 97/328~S PCT~US97/01704 As illustrated schemalically in FIG. 3, the process includes an extruder 35 adapted for e7~truding a flowable material, sL1cll as an impact copolymer resin, into a mold ~,7. The surface of the mold 37 includes a plurality of arranged cavities 39, which are adapted to foml a like plurality of surtàce stems from the flowable material. The cavities 39 may be ananged, sized and shaped as required to form a suitable surface stem structure t'rom the flowable material. ~ypically, a sufflcient additional quantity of flowahle material is extruded onto the Inold 37 to form substrate sheet 22 concurrently witll the formation of surface stems 2~. The mold 37 is rotatable and forms a nip, along with an opposed roll 41. The nip between the mold 37 and opposed roll 41 assists in forcing the flowable material into the cavities 39 ofthe mold 37, and provides a uniform substrate sheet ~'~. The temperature at whicll the foregoing process is carried out depends on the patticulal- flo-vable matel ial used. For e~ample, the temperature is in the range of l 40~ to 260~ C. for an impact copolymer resin available from Shell Polypropyletle C~ompally, Ho~Iston, Te~cas, ullder the designatioll SRD7-560.
s The mold 3 7 may be of the type used t'or either continuous processing (such as a tape, a c~lindrical drum or a belt), or batch processing (such as an injection mold), althou~,ll the former is prefen-ed. The cav,ities 39 ofthe mold 37 may be formed in any suitable mallller, such as by dlilling" machillin~" laser drilling, water jet m~c.hining casting, etchin~,, die p~lncllill<J, diamond tur~ g and the like. The plac~ nt of the 2() ca~ities 39 detemlilles the spacin~ and orielltatioll of the surface stems 2g on the substrate sheet _, and tllus on the invelltive pull roll cover. The mold cavities 39 can be open at the end of the cavity opposite the surtàce from which the flowable material is applied to tàcilitate injection of the fiowable material into the cavity. If the cavity is closed, a ~acuunl can be applied to the cavity so that the flowable material fills 2s substalltially the entire ca~ity. Alternatively, closed cavities can be longer than the lengtlls of tile stems bein~ formed so that the injected material can compress the air in the cavities. The mold ca~ities should be desi~ned to facilitate release of the surface stems theret'rolll, and thus may include all~led side walls, or a release coating (such as a TeflonTI'f material layer) Oll the ca~ity walls. The mold surtàce may also include a .~() release coatin~, thel-eollto tàcilitate release of Ihe substrate sheet fiom the mold.

CA 0224701~ 1998-08-20 The mold can be made from suitable materials that are rigid or flexible. The mold componellts can be made of metal, steel, ceramic, polymeric materials (in~lu~1in~
both thertnosetting and themloplastic polymers) or combinations thereof: The materials forming the mold IllUSt have sufficient inte~rity and durability to withstand the thermal ener~y associated witll the particular molten metal or thelmoplastic mater.ial used to fonl- the substrate sheet and surface stems. In addition, the material forrning the mold preferably allows for the cavities to be formed by various methods, is inexpensive, has a long service life, consistently produces material of acceptable quality, and allows for variations in processing parameters.
The flowable nlaterial is flowed into the mold cavity, and over the surface ofthe moldto forlll the substrate slleet. To facilitate flo~ of tlle material, the material typically must be heated to an appropriate temperature, and then coated into the cavities. This coatin~ teclllliclue can be any convelltional tecllllique, such as calendar coating, cast coating, curtain coating, die coatin~, extrusion, gravure coating, knife coating, spray coating or the like.
A~[er the thel~lloplastic matel ial has been coated into the mold cavities and over the mold sulface, the material is cooled to solidif~ and form the surface stems. The flowable matel ial is solidified itl alld 011 the mold to form the surface stems and substrate sheet, whicll are then separated t'rom tlle mold. The flowable material will often shrink 2() when it is solidified, which facilitates release ofthe surface stem and substrate sheet from the mold. Part or all of the mold may be cooled to aid in solidit~ing the sur~ace stems and substrate sheet. Cooling can be effected by the use of ~vater, forced air, liquid nitrogell or other cooling processes.
Whell therlllosettillg resills are used as the flowable material, the resin is applied 2~ to the mold as a liquid in an uncured or unpolymerized state. A~er the resin has been coated onto the mold, it is polylllerized or cured until the resin is solid. Generally, the polymerization process involves either a settin~ time, or exposure to an energy source, or both, to tàcilitate the polymet ization. The energy source, if provided, can be heat or radiation ener~ y such as an electron beam, ultraviolet light or visible light. A~er the ~o resin is solidified, it is rellloved fiom the mold. In some instances, it may be desired to further polymerize or cure the therlllosettillg resin afl:er the surfàce stem if removed CA 0224701~ 1998-08-20 from the mold. Examples of suitable therrn--setfing resins include m~l~minP, formaldehyde resins, acrylate resins, epoxy resins, urethane resins and the like. The formation of a substrate having upstanding stems on one side thereof is further detailed in U.S. Patent No. 5,505,747 and in WIPO International Patent Application Publication s No. WO 95/19242.
The frictional characteristics of the inventive pull roll cover 20 have been eslabli~hed through both static and dynamic testing procedures. The dynamic fiiction was measured between a cloth and a selected pull roll cover surface by the following procedure. A pull roll cover was formed by helically wrapping a 5 cm (two-inch) wide lo strip of the designated cover material on a 12.5 cm (five-inch3 diameter roll or core, providing a minimum of a 10 cm (four-inch) wide covered surface for evaluation purposes. The 1~.5 cm (five-inch) core, end flanges and a 2 5 cm (one-inch) shaft were mounted on a free wheeling supporting sha~. A 5 cm (two-inch) wide strip of untreated jeans cloth (specifically, 96x64 jeans cloth, 1.943 ydsAb, TencelTM fibers, available from ~s Milliken Company, SpalLanl)urg, South Carolina) was anchored at one end and placed over the designated pull roll cover material with approximately 180 degrees of wrap. A
spring scale and wire were used to rotate the core and measure the amount of force (in ounces) nec~cs~ry to move the pull roll cover material against the fixed cloth. The spring scale was a Chatillol1 scale, gauge R, Catalog No. 719-5 (0-5 lb. force gauge) (available from Chatillon, New York).
The results are tabulated in Table Il below, and demonstrate the range of friction values provided by the various pull roll cover test materials. The values are in ounces of force required to produce smootll travel between the decign~ted pull roll cover material and the 5 cm (two-illcl-~ wide strip of cloth.

WO 97/3280~ PCTrUS97~01704 Item Pull Roll Co~erTes1 Malerial Measured Load (oul~ces) B I Scolel) ~ '~ PTFE (Tcnonl ~) Filn~ Tapc :~91 E:~itmded I ~
Smooll1 B~cl~ ol'S1en1 Web (S~enl Heigl~ ypro~;. ().03()". Stem Dia.
B2 ~).()1: ". Slen1 Sptcin~ n~7 Slcm D~nsil~ 32~ sten1s/ll1~. Substr~te llliclillcss 0.00~") . O
B3 Sal'eh ~ 'T~pe~2()Fil1eResili~ntTreads B l Steol Sidc of St~m Wcb (S~llllC p.~ ;l > tS IICIII A2 ~0111 ~able 1) 10 B:~ Gllilfor(l 1~3')()~LoopClolll ~ 17 BG s~lrc~ -W~ '' T!pc 37() Mcdiulll Resilicnt Treads ~ 48 B7 BRUSH LON ' " bmsl1 lll~tetial. No. 331 B ().00~ ; (). 1 X75" Trilll 5G
T~pc L 2()~ Tilt BX BRUSHLON I ~' brusll IlI;ltCr~al~ No. 331 B ~).003" ~ 5" Trim 64 T~pc L ~()~ Tilt Notes s 1. Available as identified fi-om Mimlesota Mining and Manllf~ctllrin~
Compally~ St. Paul, l~linllesota.
2. The bacl; side (no stems) of the inventive pull roll cover material forrned from impact copolymel resin available from Shell Polypropylene Company, ~OUStOll~ Te~;as, under the desi~gnatio1l SRD7-560.
3. The front (surfàce stem) side of the inventive pull roll cover material formed fiom impact copolymel- resin available fiom Shell Polypropylene Company, Houstoll, Te.~;as, under the desi~,nation SRD7-560.

4. Available as identified fi-om Guilfol-d Mills. Inc., Greensboro, North Carolina.
The majority of these items were secured to the core using hook-and-loop mechanical attachment stnlctures. The pull roll cover test material was l~min~ted to a hool; structure backinc~ . ith the hOOl;S projectin~l oppositely from the firictional enga~ ing surface of the pull roll covel- test material. A corresponding loop structure was secured about the core tor enga~,elllellt with the loop structure backing on the pull roll cover test matelials. The llool; structul-e in this e~ample constituted either VelcroTM

I, CA 0224701~ 1998-08-20 W O 97/32805 PCT~US97/01704 8 11 , VelcroT~ 7 (both a~ailable fi-om Velcro USA, lnc., Manchester, New Hampshile) or tl1e polyolefin "musl1loom" hook fastener portion of the 3M Me~h~nic~l ~astener D;aper Closure System ~available firom Minnesota Mining and ~nllf~chlling Compal1y~ St. Paul, Minnesota). Tl1e loop structure was Guilford 18904 loop cloth, s available fi om Guilfol d Mills, Greensboro, Noltl1 Carolina.
Since a pull roll cover is typically intel1ded to prevent slippage of the fabric web and pull roll surface. a measurement of the static friction or the force required to create a slip bet~eel1 a fabric and a variety of pull roll cover test materials was perforrned. This analysis measured the horizontal force re(luired to cause movement of a two-inch by four-incl1 sulface of 14 oz. denil11 cloth against a pull roll cover material at two separate normal forces or weights on the t-~o-inch by four-inch surface. The cloth was tested with its lighter colored (back~ side fàcil1g tlle pull roll cover surface. The cloth was ancl1ol-ed to a metal block whicl1 was placed on top of a pull roll surface ~tt~,hed to a table top. The coefficient of fi iction was then calculated by dividing the horizontal force l:~ to cause slippage by the weigl1t on the two inch by four-inch surface area. The horizontAl force was measured with a Chatillon force gau~e Model DPP-50 (available from Cl1atillol1, Johl1 & Sons. Il1c., Greel1sboro, North Carolina). The measured hol-izontal forces al1d resultal1t coefficients of fiiction (COF) are presented in Table III
belo~ at botll nc:)rmal t'orces. Theol-etically, tlle coefficient of fi-iction is independent of surface area of contact and the normal force applied (for friction considered on a microscopic scale--i.e., a "sl11ootl1" surface a ,ainst a "sn1ootl1" surface). In the present case, the t'rictional effèct must be considered Ol1 a macroscopic sale (i.e., including the effèct of the penetratiol1 of the sten1s illtO the weave of the web), so the expected indepcndel1ce of COF on sult'ace area and norl11al force may not hold true.

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~~ C ~~
_ Z ~o00 ~ C ~ ~~ C~ ~ t c~
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~C ~

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CA 0224701~ 1998-08-20 W O 97/32805 PCT~US97/01704 Notes I . Available as identified fi om Minnesota Mining and Manufacturing Company, St.
Paul, Minllesota.
2. The bacl; (no stems) side of the inventive pull roll cover material, forrned from impact copolylner resin available from Shell Polypropylene Cornpany, Houston, Texas, under the desi~nation SRD7-560.
3. Available as identified from Guilford Mills, Inc., Greensboro, North Carolina.
4. The front (sulface stem) side of the inventive pull roll cover materiai, formed from impact copolymer resin available from Shell Polypropylene Company, Houston, Texas, ulldel- the designation SRD7-560.

The inventive pull roll cover (such as ltems C7 and C8 in Table III) exhibits a particular frictional perfomlance, as r eco~nized by the above testing That perforrnance can be varied, not only by varyill, certail) design parameters of the pull roll cover ~e.g., s stem hei~ t, diameter, density or spacing) but also by varying the material itsel ' Alternative materials for t'omlin_~ the pull roll cover have been mentioned above, and the frictional properties of those materials can be further altered by the use of additives (e.g., a filler) or coatin~s (e.~., a lubricious coatin~).
The si<~nificance of the mecl1allical interengagemellt component of the frictional ~() charactel-istics of the inventive pull roll cover is illustrated by tlle results of further static f'riction testin~ in tlle mannel- detailed above. The horizontal force required to cause movelllent of a two-incll by foul--incll surface of 14 oz. denim cloth or steel against a pull roll cover matelial at a nonllal force of 8.344 Ibs. on a surf'ace was measured. The cloth was tested with its li~hter colored ~bacl;) side facing the pull roll cover surface.
2~ The cloth was ancllored to a metal blocl; which was placed on top of a pull roll surface attached to a table top. Items D 1, D~ and D3 were tested on separate occasions for the cloth, hellce the additional test data. The coel~;cient of fiiction was then caiculated by dividin~ tlle hc)rizc)lltal f'orce to cause slippa~e by the wei~Jht on the two-inch by four-incll sul-f'ace area. The holizolltal t'orce was measured witll a Chatillon force gauge 3() Model DPP-~0 (available trom Chatilioll, John & Sons, Inc., Greensboro, North Carolina). The measuled holizontal t'orce and calculated coefficients offiiction ~COF) are presented in Table IV below.
- i8 -WO 97/32805 PCT~US97/01704 TABLI~ IV
l~em ~IllRollCo~rTesl Surr.7~ l~ u~llalFor~ COF
Matertal M:l~eri,71 (Ibs).atNorll~tl Force=8.341 Ibs Slllooll)B~lckofSlelllWeb Sl~l 1.77 0.2117 Dl ~b.lc~sideoflten~D2) Clolll-lsl ~.33 (.7.39g4 Clotl~-211d ~.3 0.2756 StelnSideorSIelllWeb St~l l.X 0.21~7 D2 (~mepa~mele~orllem A2 fi~ Tabl~lhe~in) CJotl~-ls~ 3 0.7231 ~loll~-~nd ~.()7 0.7275 SlelnSide Orslclll Wcb St~l 19 0.2277 D........ ~llncp;lr.llllctc~ofllc A-rrolllT.lblclllcrc~
Clotl~-lst ().1~ 0.73~1 Clolll-2nd ~.76 0.6903 Slem SideofSlem Web Dl (~lne~.".,.~ orltcltl Sl~l 1'~ 0.2277 AlfirolllT~Iblel hcreill) Clolll (.11.- 0.7231 The pull roll cover test matel-ials in Table IV are either the back side (Item Dl -no stems) of the invetltiVe pull roll cover material, or its front side (Items D2, D3 or D4 - surface stems), and all were formed fi-om an impact copolymer resin available from Shell Polypropylene Con7pall!~, Houston, Te,~;as, under the desi~nation SRD7-560. The coefficient of fi-iction for each of the diftèrent pull roll cover test materials in Table IV is mucll lower for the steel sultàce than the coefficients of fiiction t'or that same material in relationsllip to the clotll sulfaces. The diftèrence is believed to be the result of the 1(~ mechanical intelellga;,eltlellt of the surface stems and weave of the cloth. and its contl-ibutioll to the fiictional interrelatiol1ship between those two materials. As can be - seen by a comparison of the steel coefficients of fiiction al7d the cloth coefficients of friction in Table IV, this contribution is significant.
In addition to the invetltive pull roll cover '~0 itself, the present invention relates 1~ to tlle apparatus and metllod for use of a r eadily replaceable and repositionable pull roll CA 022470l~ l998-08-20 W O 97/32805 PCT~US97/01704 cover The inventioll allows relatively quick challgeover t'rom one cover to another on a pull roll by a simple and efflcient arran;,emellt that results in low maci~ine downtime Ln addition, the present invelltiotl does not require special handling or expertise (eg, hazardous waste disposal) in the pull roll cover replacement process Previously, opposed hook-and-loop fastener structures have been used to secure pull roll covers to pull rolls In all sucll instances, l-owever, the hook structure material was mounted onto the pull roll The pull roll cover then had loop structure material on its back side, and was helically wrapped about the pull roll with llook stmcture material mounted thereoll Occasionally, one or more hooks protruded (because of an imperfect helical wrap of the plJIl roll cover) fiom the pull roll exterior to contact the fabric web in use~ piCi';ill~ and tearing at the tàbric web as it traversed the pull roll cover Any change to the surface of the cloth or its weave produced by the pull roll is considered to be dama~e to the cloth and is thlls to be avoided The puil roll cover altachmellt of the present inventiol- involves securing the loop material on the pull roll instead of the hool; material The loop material is bonded around the cylindrical outer surface of tl-e pull roll The loop material is pl~;rel~ly secured to the pull roll by a non-repositionable adhesive, since the loop material would rarely be removed or need replacement once secured onto the pull roll The loop material, even if e~posed by an impeltèct spiral wrap of the pull roll cover over it, does not picl; at the fabric traversin=, the pull roll~ and thus si~nificantly ~ S the possibilitv of damage to the làbric weave The hool; material used to secure the pull roll cover to the pull roll now projects away fron- the textile web, thereby preventing the possibility of picl~ing or tearil-~ the te~;tile as it traverses the pull roll FIG 4 iilustrates the pret'erred method for the appiication of a strip of loop 2~ stmcture material 45 about the cylindrical outer surface of a pull roll 47 The loop structure n-aterial 4~s is applied in a l~arro~ strip e g, '~ 5 to 10 cm (one to four inches) wide wl-apped l~elicallv about a cylindrical outer surfàce 49 of the pull roll 47 The entire cvlindlical outer SUI fàce 49 of the pull roll 47 (or at least that portion of the pull roll that contacts the te~;tile ~A~eb) is covered in this mal~l-er with the loop stnucture n~ateriai 45 An adhesive (such as a pressure sensitive adhesive) is used to secure the loop material 45 to the pull roll 47 ~() CA 022470l~ l998-08-20 W ~ 97/32805 PC~AUS97~01704 The extelior pull roll cover material is bonded to a hook structure fastener material such that one majol side of the pull roll cover (itS inner side) has ~t~nin~
hool;s projectin~r thel-efrolll while the otller side (its outer side) has the desired ~ictional engagin~ sulface projectilt~ thel efrom (for engagin~, and traversing a fabric web), tl~ereby definin~, a pull roll cover assembly for application to the pull roll. The pull roll cover assembly is also preferably applied as a long narrow strip (e.g., one to four inches w;de) which is helically wrapped around tlle pull roll. FIG 5 illustrates the application of a strip of a pull roll cover assembly 50 about the pull roll 47. The pul~ roll cover assembly 50 is llelically wrapped about the loop fastener structure 45, and can be I () oppositely wound relative to the windillg of tl-e loop fastener structure 45 (as illustrated in FIG. S) if desired. The use of hool~-and-loop fastening structures allows some slight axial or side to side play of the pull roll cover assembly 50 as it is being helically wrapped. This allo~s for the efficient achievemellt of fairly precise edge-to-edge wrapping, witllout the necessity for continued removal and repositioning of the pull roll 1:~ cover assembly 50 to properly and completely cover the pull roll 47.
While a pretèrl-ed embodimellt includes the application of narrow strips of loopstructure material 45 and pull roll cover assembly 50 in a helical wrap about the pull roll, otller application configuratiolls are possible. For installce, one or more lnngitll-lin~lly aligned strips may be adhered to tlle pull roll.
2() F~G. 6 illustlates, in more detail, the nature of the pull roll cover assembly 50 and its n~oulltillg tO the p~lll roll 47 [wllicll has a backing substrate sheet 51 of the loop structul-e material 45 adheled to itS cylilldrical outer sultàce 52). The pull roll cover assembly 50 has its extel-ior side defined by the invelltive pull roll cover 20. As such, the swface stems 28 ofthe cover 20 project outwardly from the substrate 22, with the outer 2~ ends 30 of the sur~ace stems 28 definillcg the cylindrical textile engaging surface of the pull roll 47.
On its opposite side. the co~er assembly 50 has means for hooking the loop stmcture material 45. 1n FIG. 6, the hooking means is illustrated as a sheet of hook stmcture material 53 havillg a supportive substrate 54 ~'ith an array of projecting hook 3() stems 55 Oll one sicle thel-eot, with each stem having at least one head 56 thereon for CA 0224701~ 1998-08-20 W O 97/32805 PCT~US97/01704 interen .a~ement with the looped and intel-l11in(Jled hook-enga~ filaments of the loop structure material 45.
Ti1e opposed substrates ''~ and 54 are bonded together to define the cover assembl~ 50 as a surface substrate sheet, with sutface stems 28 projecting from one side and hool~ stems S~S projectil1~ tiom its other side. A suitable adl1esive for IA~ the invel1ti~e pull roll cover 20 to the hook stmcture material 53 is ScotchTM 985 Ilaminatin~r adhesive, available from Minnesota Minil1g and ~nufac.t~lring Company, St.
Paul, l~innesota. An alternative adhesive is Scotch~M 919 laminating adhesive, also available from Minnesota Minil1~ and Manufacturil1g Company, St. Paul, Mi~ esuLiL.
Tlle particular laminatil1g adhesive used depends upon the characteristics of the compositions used to t'orm tlle pull roll cover ~0 and hooli structure material 53. Ir~ any event, the lamil1atioll is intellded to be pennallel1t and no separation of the facing substrates of the two materials. once bonded together, is desired. Webs of the pull roll cover ')O and hool; stl~lctul-e material 53 (wllicl1 may or may not be fo~ned ~om the 1~ same material) are laminated by fèedin2 those webs from rolls, removing and winding up any necessary adhesive liners, and bril1~ , the laminatin~ surfaces together in a rolling nip ul1del controlled tension and pl-esslll-e. The joined materials are then slit with a rollin(r };nife and wc)ul1d on cores to produce strip rolls of the pull roll cover assembly S0. Tlle widtl1 of each pull roll cover assembly strip roll preferably ranges from 2.5 to 2() 10 cm (one to tour incl1es) and, more preferably, fiom S to 7.5 Cltl (two to three inches).
As met1tiol1cd above~ in a preferred embodiment, the pull roll cover used w.ith a pallicular pull roll should not be so tllick as to si~3nificantiy modi~'y the effective diameter ofthe pull roll. Thus, in a pretèrl-ed embodimel1t, a low profile hook-and-loop fastener structure assembly is desired so that the attachn1el1t means for the exterior pull roll cover '~ sulface is as thil1 as possible. The hook structure material 5~ and the loop structure matelial 45 are tllus mated in terms of tlleir cllaracteristics and structure to provide sufficient bondin~ stren~Jtl1 but maintain a relatively low profile.
The loop structul-e material 45 can be either l;nitted loop, warp knitted loop fabric, stitched loop tàbric, wovell Ol nol1wovel1 loop fabric. The loop structure material 3~) 45 l~resel1ts intelmill~led fibers f'or en~a~,ell1el1t by the hoolis 55 of the hook structure n1atelial S~,. Pretèrably, the loop structure n1aterial 45 includes a plurality of loops 60 CA 0224701~ 1998-08-20 W ~ 97/32805 PCT~US97/017M

comprising filaments anchored tOt11elOOp structure substrate 54 at each end. The hook stems 55 thus become entangled in the loops 60 to attach the cover assembly 50 to the pull roll 47.
Tlle loop stl~lcture nlaterial 45 should be such tllatitis easy, i.e., without much s effort Oll the operatol~s part~ to en~age the l~ook stems 55 into the loop structure material 4~;. Lil;ewise, wllen the cover assembly Sû is to be replaced, the operator should be able to easily remove the cover assembly 50 from the pull roll 47 by disengagement ofthe opposed l1ook-and-loop structure materials.
If the loop height is too high, it can lead to shifting of the cover assembly 50, () W}l;Ch could lead to notl-ut1iforl11 contact with the advancing fabric web and scuffing or marrin2 tllereof. Tf the loop heigl1t is toO lo~, thel-e may be insufficiellt interengagement and attachlllellt ofthe hool; stems 5j and loops 60. In ~eneral, the height ofthe loops sllould be of the same order ot'magl1itude as the height of the hook stems. Additionally, the loop dimensions and oriel1tations may depend upon the shape and height of hook ]S stems pro~ided.
Tlle loop density may also be selected to provide suitable p~ l"ance charactetistics. For e~ample, tlle density of the loops can be the same as or di~erelll fi-om the density of the l1001';S. If the loop density is too hi~h, this increases the cost of tlle loop str ICtUre material~ alld it may be difficult to disen_age the opposed hook stl~lcture material. If the loop density is too low, there may be insufficient peel and shear strength to maintain the cover assembly 50 in place during use.
The loop structure matelial 45 includes a plurality of loops 60 comprising filaments ~hicll are intermingled to~ethel; as illustrated in FTG. 6. The filaments may either be individual filamellts, or yams complisillg a group of twisted filaments. The 2s filametlts should be r elatively strong to eff'ectively hold the hook stem and not prematurely release the l-ooi; stem. E~iamples of such materials include inorgarlic fiber filaments, such as metal ~includitl~ alulllillum or steel), ceramic (including glass and fibe.rglass~ and the like The filamellt may also be a combination of dirre~l" materials.
Tlle filament may be straigllt, curved or twisted, and may contaill a surface LI~L~llc;llL of .() some type, sucll as an antistatic coating, I~lbricious coatino. etc. Examples of organic based filaments inclllde both tllerllloplastic and themlosettillg materials like polyamides, CA 022470l5 l998-08-20 W O 97/32805 PCT~US97/01704 polyolefins, pol~urethanes, aramides, polyester, cellulosic materials and the like. In general, it is pretèrred that the filamel1t diameter be one-half the distance that the head 56 overhangs from the stem of tl1e hook stem 55.
The loop structure material 45 can be bonded directly to the exterior sur~ace ofthe cylindrical pull roll 47 (i.e., thermoplastic loops can be melt bonded thereto).
Alternatively, a la",;natin~ adhesive can be used to secure the loop structure material to the palll roll. Examp1es of laminatillg adhesives include polyolefins, polyesters, polyurethanes, polyamides, hide glue, rubber based adhesives, urea-formaldehyde adhesi~es, epoxy adhesives, acrylate adhesives and the like.
n A preferred loop material is Guilford 18904 loop cloth, available from Guilford Mills, l11C., Greensboro, Nortl1 Carolina. This knitted loop cloth has a low profile (approximately 0.3 mm (0.01'' inch) tl1icl;). A scrim l1as loop fibers on one side thereof, and is provided witl1 an aclylic pressul-e-sensitive adhesive Oll its other side, which allows easy bondin~ ot'the loop cloth to the exterior cylindrical surface of the pull roll.
Is A suitable adhesive for this purpose is A210 pressure sensitive adhesive film, avai]able from illbruck, inc.~ IVinneapolis, Minnesota.
The hool; structure material 53 for the pull roll cover assembly 50 also has a relatively low profile, and preaèrably is formed from hool; stem materials such as those disclosed in Melbye et al. IJ.S. Patent 5,077,870; Chesley et al. U.S. Patent 5,505,747, 2(1 and WIPO Interl1atiol1al Patent Applicatiol1 Publication No. WO 95/19242. One version of sucll malel-ial is the 3M Mechanical Fastener Diaper Closure System (available t'rOIll Mhlllesota Mjnjl1~J and Manufacturing Company, St. Paul, Mir~esota~.
111 a preferred embodiment, the l1ool; structure mate~ial 53 is foamed with the following characteristics: stem heigllt = approxilalately 0.5 mm (0.0'~0 inches), stem c~i~met~r=
2~ 0.4 mm (0.016 inclles), head diametel- = 0.76 mlll (0.030 inches), stem spacing =
1.4 mm (0.055 hlches), and stem density = 50 stems/cm~ (3''5 stems per inch2). The hool; stems 55 are formed intega-ally with substrate 54 (whicl1 is 4.5 to 5 mil thick), preferably of SRD7-560 impact cola~olymel- resill, available from Shell Polypropylene Compal1y. Houston. Texas.
3() Alten1ative hook struct-lre matelial t'oamations are also contemplated. As used herein, hooli steln means a stem havit1~ a free end that is spaced fi-om the surface to CA 0224701~ 1998-08-20 W O 97/32805 PCT~US97101704 which the stem is attached and a structure that enables the hook stem to releasably hook the features of the enga~ing sulface ~loop sh-ucture material). In FIG. 6, each hook stem 55 is illustrated as having a head 56 shaped in the form of a nail head. Alternative hooi; stem and head configuratiolls ~vill iùnction to suitably en ,age the loop structure material. For instance, the head may have any suitable three-dimensional shape, such as a hemisphere, sphere, IllUSIll'OOlll cap, cube, pyramid, etc. Preferably, the head has at least one undercut portion that e~tends radially away from tlle stem at a right angle, such as the heads ~6 shown in FIG. 6, to hook loop filaments of the loop structure materiai 45. Also. while the arran~ement and formation of hook stems on the hoolc structure n material ~3 are illwsts-ated as <renerally uniforlll, alternative stem patterns, such as non-ullifol m stems and stem array arran~emel1ts, will suff;ce.
A pull roll co~er assembh~, such as described above and illustrated in FIG. 6, combil1ed witl1 the prefèlred loop ancl hooii materials desclibed above, plere,~bly has a thici~ness of less thal1 0.~0 inch, more prefèrably less than 0 '~ inch, and most preferably 1:~ less thal1 0.09 inc.h, th~ls definil1g a relati~ely IQW profile coverinC1 for the pull roll. The lovv Ioft of the Guilt'ol-d 18904 loop cloth ~as significant in its selection as a pler~ d loop structul e matelial for this purpose.
The embodil11el1t illustlated in FIG. 6 uses both the low profile pull roll cover 20 having upstandil1~ sulface stems ~g, and the disclosed low profile pull roll cover 2() attachmellt means. The pull roll cover assembly ~0 is readily replaceable relative to the pull roll ~7 bearin,g the loop stlucture matel ial 45 on its extelior cylindrical surface 52.
Whell a challge in pull roll covers is dcsired, the pull roll cover assembly 50 can be removed by disengagil1g the hooii slen1s ~ on the hook structure material 53 from the loops 60 of the loop stmcture material 4:n A replacel~1el1t pull roll cover assembly, ~5 havis1g one side defined by a replacemellt textile en~agillg~ material and the other side defined by a suitable hooi~ tàstener stmctule, is then aftixed to the pull roll by adhering the hooi~ fastener structule thel-eon to the loop fastener Stl~ctul e on the pull roll. The replacement pull roll cover assembly is also typically applied as A thil1 strip, helically wrapped about the pull roll, as illusn-ated in FIG 5. Replacement can be performed ~,() simply to replace a worn pull roll cover witl1 anotl1er having the same filctional and mechanical engagel11ellt properties, or to replace a pull roll cover with another pull roll CA 0224701~ 1998-08-20 W O 97/32805 PCT~US97/U1704 cover llavillg diffèrellt fiictional and mecllallical en~agement properties. For instance, with respect to the invelltive pull roll cover 20 illustrated in FIGS. 2A, 2B and 6, different i'rictional and mecllallical engAaement characteristics may be achieved by substitutill(~ a different pull roll cover of the same general structure, but having di~
surface stem densities, spacin; ,s, hei<~llts or diameters, or being formed i'rom a dil~
(i.e., less lubricious) material.
Ttle use of the inventive hook-and-loop fastener arrangement of the present invention thus provides i'or a wide range of pull roll cover options for the same pull roll.
The different pull roll cover materials can be readily replaced because of the ease and l(~ effectivelless ofthe inventive attachlllellt an-allgement wllele the loop structure material is essentially pellltallelltly attached to the pull roll, while the hook structure material is adllered or formed on the bacl; of the pull roll cover. This is iliustrated, for example, by FIG. 7, w hereill a pull roll cover assembly 150 has a pull roll cover 120 formed from an alternative material. This could include any of the types of pull roll cover materials :~ mentioned hereill, such as cork, lubber, sandpaper, bristle brushes, films, cloths, TeflonT~ substrates, polymeric coatings, pol~mel-ic coatings containillg additives, coated abrasives, nonwoven abrasives, slllootll or textured polymeric films, glass co~tin~
paper, foam, noltwoven materials, metal foils, and otller materials, such as those listed in Tables ll and 111. Anotllel- pull roll cover matelial is a microreplicated surface, such as a structural abrasive article, available under the trade desi~mation 207~A structured abrasive article. i~ Olll Minllesota 1\1inin~, and Manutàcturill~, Company, St. Paul, Mhlllesota. The possible pull roll cover nlatel-ials are limited only by the desired frictional chal-actel-istics of sucll materials, and their suitability for use in a particular te~tile pull roll applicatioll. The altemative pull roll cover assembly l S0 has a cover 120 2: with an e:;terior textile enga~in~ surface on one side, and on its opposite side, it bears a hool; structule maIel-ial or structule such as hook stlucture material 153. This hook structure matelial 1S3 hl tUIIl is releasably engageable with loop structure material 145, wllicll is bollded to cylindrical outel sulfàce 152 of pull roll T47. The cover assembly IS0 can thus be rellloved i'or replacenlent or change with another pull roll assembly .~) havin~ the same or dii~'erellt fi ictional engag~elllellt characteristics. as desired.

-- ~6 -CA 022470l~ l998-08-20 W O 97/3280~ PCT~US97101704 FIG. 8 illustrates yet another emboditnent of a pull roll cover assembly 250. Inthis embodiment, no separate or discrete exterior pull roll cover is provided. The exterior (pull roll) surface of the pull roJl assembly 250 is defined by the side or surface 1251 of llOOIi structure material ?53 opposite its hook stems ?~5 The hook structure material '~53 is again releasably en~,a~,eable with loop structure material 24~ adhesively bonded to cylindrical outer surface ?~S2 of puli roll 247. The exterior surface 251 of hool; structure material ?53 itself serves as the textile en;,a;,emellt surface of the pull roll cover. The frictional characteristics for two versions of this type of pull roll cover assembly are listed in Table ll (ltem B2)~ Table III (Item C?), and Table IV (Item Dl).
The invetltive pull rolt cover ?O of the ;nventive embodiments described above overcomes many of the disadvanta~Jes of the prior art. It provides a pull roll cover ha~'ill;, illitiall~,' UllifOI-Ill and extremely consistent fi~ictional engagement characteristics, which includes contrc)lled and noll-ablasive mecltanical en~a~ement with a textile web traversed thereby. The inventive pull roll cover 20 has a low profile and ll~i.;"l~in~ its engagement properties unifomlly dutin~ wear of its surface stems. The pull roll cover surface stems do not picl; or tear at a textile web, it is resistant to the transference of dye from one textile web lot to al1othel-, and il does not e:;hibit a buildup of lint and fibers durin~ use. The invelltive pull roll cover ?(), wllell combined with the inventive hook-and-loop fàstenel mealls tor attachill~S a pull roll cover to a pull roll (with the loop ~0 structure material bonded to the pull roll)l results in a superior, low profile, inexpensive and easy to use pull roll cover replacemel1t arran~el1lellt. The unique and inventive attachmetlt arrallgelllel1t eliminates the possibility of dama~,e or picl;ing of the web by the attachment components themselves The present invetltiol1 filrther relates to an apparatus and method for use of a~5 readily replaceable ~or repositionable), low profile pull roll cover. The invention allows relatively cluicl; chan~reover fi-om one cover ~o another on a pull roll by a simple and efficient arral]~el11ellt that results in low macl1il1e downtil11e. In addition, the present invel1tiotl does not require special halldlitl~, or expertise (e.~., hazardous waste disposal) in the pull roll cover replacemellt process~ and it provides for an extremely low profile pull roll cover attachlllellt. The present invelltioll simplifies the cover application and CA 0224701~ 1998-08-20 W O 97/32805 PCT~US97/01704 replacement process~ since it does not necessarily require the application of a fastener matelial onto the pull roll prior to application of the pull roll cover itself.
Wllile the invel1ti~e en1bodinlents described above with respect to FIGS. 4-8 provide man~ advanta~es and are pai-ticularly well suited for many applications, such two-part fastenin~ arrangemellts re~uire additional material and add depth to the pull roll cover.
The pull rol] cover attachment of the embodiment described with respect to FIGS. 9-1'~ involves securing the pull roll cover directly onto the pull roll by means of a repositionable pressure sensitive adhesive (PSA). A repositionable pressure sensitive I () adhesive is a low tacl~ adhesive. havill~, sufficiellt adhesive qualities to maintain an article in place once applied to a sult~ce, but allowin(J tlle adhesive to be overcome if it is desired to reposition or rell1ove the article. The repositionable adhesive leaves no appreciable resid~le once rellloved, alld retains sufficient tacl; to be re-adhered once repositioned on a mountin, surface. Repositionable pressure sensitive adhesives are 1~ filrther described in U.S. Patent Nos. 3,691,140 and 4,166, 15. . This ~tt~-.hm~nt arrall~,elllellt for a ~I)ull r oll covel- does not appreciably add to the radius of the pull roll covel-, thus creatillg a ver~ lo~t pl-ofile pull roll cover assembly. Fulther, no undesirable residue is le~ on the pull roll whell covel-s are changed.
FIG 9 illustrates the l.~retèn-ed metllod for the application of a strip of pull roll 2() cover 320 about the cylindrical outer sul1àce of a pull roll 47. Tlle pull roll cover 320 is prefel-abl~ applied in a nalrow strip~ e.g,., '~.~ to 10 Clll (one to four inches) wide wrapl)ed helicall~ about a c\~lindlical outer surface 49 of the pull roll 47. The entire cylindl ical outer sultàce 49 of the pull roll 47 (or at least that poltion of the pull roll that contacts the textile web~ is covered in tllis manller with the pull r oll cover 320. While a 2~ helical application is shown, other alignmellts are also possible.
FIG. 10 illustrates, in more detail, the nature of the pull roll cover 320 and its moulltil1g to the pllll roll 47. When mounled as shown, the surtace stems 328 of the pull roll cover 3'?0 projcct outwal-dly ti-OIll the second side 3'~G of {lle substrate 322. The sultàce stems 328 thils detine the c! lindl-ical operative textile contact surtàce of the pull 3(~ loll 47.

- ~s -CA 0224701~ 1998-08-20 W O 97t32805 rcTnuss7~ol7o4 On its opposite side (first side 3?4),the substrate 3'~2 of the pull roll cover 320 is bonded to the cylindrical outer surface 49 ofthe pull roll 47 This bond is ~)le~ bly achieved by a laminatillg adl~esive assembly, as more speci~ically illustrated in FIG 11 (as meîltioned above, the drawillg f~ules are not to scale, pOltiOllS being enlarged for s clarity) A slleet or scrim 69 ilas its first side 71 bonded by a nonrepositionable pressure sensitive adhesive layer 73 to tlle second side 3'~4 of the substrate 322 The particular nonrepositionable adhesive selected depends UpOIl the characteristics of the compositions used to form the substrate 322 of tlle pull roll cover In any event, the lamination of slleet 69 to substrate 3 _ is intended to be permanent 1() On its second side 7~, the sheet 69 is bonded to the cylindrical outer surface 49 ofthe pull roll 47 by a low tacl; pressule sensitive adllesive layer 77 This lamination is intended to be repositiollable in nature, so that the pull roll cover 320 may berepositioned (or renloved) relative to tlle pull roll 47 by release of the low tack repositionable pressure sensitive adllesive from the cylindrical outer surface 49 :. In a preferred embodimellt. these low tacl; adllesive properties are provided by Scotcllmarl;r~' 9870 High-Low lacli Lamillatillg Adhesive, available from Minnesota Minill~ and Mallufact~llill~g C~ompall~, St Paul, Minlleso~a Tlle Scotchmark~M 9870 laminatill~, adhesive llas a polyester scrim or carlier (sheet 69~ This prevents any bleed thl OUy,ll of nolll epositionable adllesive toward the cylindrical outer surface 49 of the pull 2() roll 47~ and th-ls lessens the likelihood of ally nonrepositionable adhesive residue being le~ on the sul1àce 49 Webs of the pull roll cover and lamillatin~r adhesive are laminated by fèedin~r those webs fi-om rolls~ renlovill(r and willdilt, up any necessary adhesive liners, and blin;,ill~J the layer 7~. of nolll-epositiollable adllesive together against the second side 3'74 of the pull roll co~er substrate 3~'~ in a rollillg nip under controlled 2s tension and pressllre The joined materials are thell slit wit11 a rollin~ knife and wound on cores to produce Stl ip rolls of the pull roll cover The widtl~ of each pull roll cover assembly strip roll ran~,es fionl '~ ~ to 10 Clll ~one to four inches). and preferably from S
to 7 5 Clll (tWO to thl-ee inclles) A linel- relllaills over tlle laver 77 of low tack pressure sensiti\!e adilesive, to be relnoved LlpOIl application of the pull roll cover to the cylindrical outer sultàce 49 of a pull roll 47 ~9 CA 0224701~ 1998-08-20 W O 97/32805 PCTrUS97/01704 As mel1tioned above, in a prefèrred embodiment, the pull roll cover used with a particulal pull roll should not be so thicli as to significal1tly modify the effective rii~m~ter of the pull roll. The thicl;l7ess of the Scotcl-mate'~ 9~70 larninating adhesive is approxil11ately ".5 mil, and th-ls provides an attachment means for the exterior pull roll cover which adds no appreciable increase to the pull roll diameter. Any change in diameter behveell pull roll covers on a single pull roll tl-us depends on the thjr~n~cc of the pull roll covers then~selves, and not on theil- repositionable pressure sensitive adhesive attachment nieans. Tl1e pull roll cover, such as described above and illustrated in FIG. 5, preferably has a thickl1ess of less thal1 1."7 cm (0.500 incl1es), more p~e~el~bly less thal1 6.4 mm (0."~0 incl1es), and n1ost pretèrably less than 1.3 mm (0.050 inches), tl-us definil1g an extremely lo~ profile covering f'or the pull roll.
Othel suitable pressure sel1sitive adhesive arrangemel1ts are contemplated. For instal1ce, a noniepositiol1able pressule sensitive adhesive can be laminated on the second side 324 of the substrate ~ , with a lo~ tack pressure sensitive adhesive larrlinated over the hi~l1 tacl; adhesive. Suitable pressllre sensitive adhesives for this purpose are Scotcl1 ' '1 919 Lan~il1atil1;, Adhesive and Scotch ' 'l 9449 Laminating Adhesive, respectivel), both available fi-om Minl1esota Minil1g and Manufàcturil~ ompany, St.
PauL I\ linnesotct. A<~ain, this adhesive an-al1gel11el1t is extremely thin, preferably accul11ulatil1~ to less thal1 0.0~0 mil. For tlliS specific arran;,emel1t, over time (e.g., 30 days), the nonrepositionable adhesive will bleed througl1 to the low tack adhesive, and the repositionable characteristics of tlle low tacl; adhesive will deteriorate.
The embc)dimel1t illustlated ill FIG. lO uses botl1 the lo~v profile pull roll cover 3'~0 havil1~ upstandin~ sultàce sten-s 3'~8~ and the disclosed vely low profile pull roll cover attachn~el1t meal1s. Wl~en a chan~e in pull roll covers is desired, the pull roll cover 3'~0 is sin-ply peeled away fi-om the cylindl-ical outer surtàce 49 of the pull roll 47 to separate the repositiol1able ~ - tacl;) pl-esslll-e sensitive adhesive layer 77 from the cylindl-ical outer sultàce 49 of the pull roll 47. A replacen1ent p~lll roll cover, having one side defined by a replacen~el1t textile en,a_ing material and the other side bearing repositionable press~lre sensiti\ e adl-esive~ is thel1 applied to Ihe pull roll 47 by wrapping it about tl~e pull rc)ll 47 and pressin~ it tllereto. The replacel11ent pull roll cover is also typically applied as a thil- Stlip~ helically ~vrapped about t'he pull roll as illustrated in FIG.

, ~ ) CA 022470l~ l998-08-20 W O 97/32805 PCTrUS97/01704 9. Replacement can be pertolmed simply to replace a wom pull roll cover with another havillg the same fiictional and mechallical enga(rement properties, or to replace a pull roli cover with anotller pull roll cover havillg different desired fi ictional and mechanical en~agement properties. For instal1ce, with respect to the inventive pull roll cover 20, 320 illustrated in FIGS. 2A, 2B and 10, diffèrent desired frictional and mer,h~n~
enj~,a ,ement characteristics may be achieved by sub.stitllting a different pull }oll c~ver of the same general structure, but having dillè~ enl surface stem densities, ~racing~, heights or diameters, or bein~ formed from a diffèrent (i.e., less lubricious) material. There is no appreciable adhesive residue buildup from one cover to the ne~t on a pull roll, so that 1() the initial diametel- of tllat pllll roll is mailltailled over time and various pull roll cover applicat ions.
Tlle use of the inventi~e repositionable pressure sensitive adhesive pull roll fastenil1~ all-al1;,ement of the presellt invelltion tllus provides for a wide range of pull roll cover options for tlle same pull roll. The different pull roll co~,er materials can be readily s replaced (or repc)sitioned if initially misali~rlled during application) because of the ease and eftèctiveness of tlle in~entive attachlllent arranrelllellt. This is illustrated, for e,~;ample. by ~IG. 12~ llereill a pull roll cover 4'~0 is t'ormed from an alternative matelial or structure. The cover 420 could include anv of the types of pull roll cover materials mentioned hereill, such as corl;, rubber, sandpaper. bristle brushes~ ~ilms, cloths, Teflonr~ substlates, polymeric coatin~rs, polymeric coatings conti~inin~r additives, coated abrasives, nonwovell abrasives, polymeric filnls, ~lass coatin~,s, paper, foam, nonwovell materials, metal foils, te~;turized pol~mers and other materials, such as those listed in Tables 11 and 111. Anolllel pull roll cover material is a microreplicated surface, such as a structul-ed abrasive alticle, available undel- tl~e trade designation 207EA
2:- stmctuled abrasive alticle. available t'rom Minnesota Minin~r and M~n-lfactllring Compally. St. Paul~ Minnesota. The possible materials are limited only by the desired frictional cl-arac.teristics of sucll materials~ and their suitability for use in a particular te:;tile pull roll applicatioll. Tlle alternati~e pull roll cover ~''0 has an exterior textile en~ra~,in~, sult'ace 421 on one side. and on its opposite side ~22, it bears a layer of .~1) rel70sitionable pressure sensitive adl-esive ~ihich is brou~llt illtO adhering contact with the cylindlical outel- sult'ace 49 of pull roll 47. The pull roll cover 420 can thus be easily CA 0224701~ 1998-08-20 W O 97/32805 rCT~US97/01704 and e'r'ficiently removed for replacement with another pull roll cover having the sarne or linè,enL f'rictional and mechallical engagement characteristics, as desired.
The pull roll cover of the inventive embodimellts of FIGS. 9-12 overcomes many of tl-e disadvantages of the prior art. It provides a pull roll cover having initially unifornl alld e~;tremel~ consistellt frictional engagelnellt characteristics, as well as the possibility for contlolled and noll-abrasive mechallical en~a~r,emellt with a textile web traversed thereb)~. The invelltive pLlll roll cover has a low profile and maintains its enga~r,ement properties ullif'omlly durin_, wear of its surface stems. The pull roll cover surface stems do not pick or tear the textile web, it is resistant to the transference of dye from one textile web lot to anothel-, and it does not e~hibit a buildup of lint and fibers dUrill~r LISC. l~he pull roll cover, wllell combilled witll the inventive repositionable pressure sensitive adhesive f'or attachin~ a pull roll cover to a pull roll, results in a superiol. e ;trelllei~ low profile, ine.~;pellsive and easS~ to use pull roll cover replacement arrangemellt The ullique and in~ellti\~e attachment arran~,ement elii-ninates the possibilit~ of dama~,e or piCl;ill(J, of the te~;tile web by the pull roll cover ~ttachm~n~
arrangement.
Althougll tlle present in~!elltioll llas been described with reference to preferred embodinlellts, woli;ers sl;illed in the all will reco~,llize tllat cllall,es may be made in forlll and detail ~itllout departhlc fiom tlle spirit and scope of the invention. For 2() installce~ t11e base stnict~lre f'or applicatioll of tlle invelltioll has only been described with respect to c~,~lhldrical pull rolls. The hlvelltive cover and the novel cover attachment method disclosed heleill can be applied to othel base structures. such as an endless belt or other s~lrf;ace wllicll may come into contact witll an advancill~, te~tile web in a textile processill rr ol mall~lfàct~lrill~ iacility Fultller, the hlventioll is also applicable in applicatic)lls otl1er thall te.~;tile pull rolls. Any surfàce whicll contacts a web or sheet or otllel- substl-ate worl;piece is a candidate 'r'or tlle hlventive co~er and inventive cover attacillllellt arran;,elllellt of the present invelltioll. For installce. the roll cover can be applied to a one-illcll diameter trallsfèr rc ll in a photocop~,~ machine In this regard, possible web materials ma~ include, but are not Ihtlited tO, wovell, nonwoven, knitted, .~() needle tacl;ed, wet laid. stitch bonded and SpUIl bonded matelials, as well as papers, films~ t'oils~ and lnetal sheets or strip~ F~llthermole, the orielltation of the lan~inating - 3~ -W 0 97132805 PCT~US97J~7W

adhesives described ~vitll respect to FIG. I l may be reversed such that the nonrepositiotlAble adllesive tàces the puli roll surface and tlle repositionable adhesive is exposed on tlle pull roll (so tllat the ret)ostiollable adhesive is on tl)e pull roll rather than the on the replaceable cover). Alterllatively, a discrete sheet havillg repositionable pressure sensitive adhesive 011 both its sides may be disposed between the roll and roll cover.

Claims (56)

WHAT IS CLAIMED IS:

1. An engagement apparatus for use on a textile pull roll having a cylindrical outer surface which traverses an advancing web, the engagement apparatus comprising:
a surface substrate sheet having first and second sides, the second side of the sheet having a plurality of surface stems projecting outwardly therefrom, the surface stems being disposed in a selected arrangement on and formed integrally with the surface substrate sheet, each surface stem having a constant diameter along its height, the surface stems being generally uniform in height, and outer ends of the stems collectively defining an operative web contact surface; and means for releasably securing the first side of the surface substrate sheet to the cylindrical outer surface of the roll.

2. The engagement apparatus of claim 1 wherein the securing means comprises opposed hook and loop fasteners on the first side of the surface substrate sheet and at least a portion of the cylindrical outer surface of the roll, with the loop fasteners being on the cylindrical outer surface of the roll and the hook fasteners being on the first side of the surface substrate sheet.

3. The engagement apparatus of claim 1 wherein the selected arrangement is a uniform array.

4. The engagement apparatus of claim 1 wherein the surface stems are uniformly shaped.

5. The engagement apparatus of claim 1, wherein the securing means comprises:
a repositionable pressure sensitive adhesive disposed on the first side of the surface substrate sheet to allow releasable adherence of the surface substrate sheet to the cylindrical outer surface of the roll for replacement or realignment, the repositionable pressure sensitive adhesive being a low-tack adhesive that retains sufficient tack to be re-adhered once repositioned on the outer surface of the roll and that leaves no appreciable residue once removed therefrom.

6. The engagement apparatus of claim 1, wherein the securing means comprises:
hook-engaging structures on said cylindrical outer surface, and a plurality of hook projections extending outwardly from the first major surface of the cover substrate, wherein the hook projections each include means for hooking the hook-engaging structures to releasably affix the surface cover assembly to the opposed surface.

7. The engagement apparatus of claim 1, wherein each surface stem is cylindrically shaped.

8. The engagement apparatus of claim 2, wherein the surface substrate comprises: a first sheet bearing the surface stems; and a second sheet adhered to the first sheet and bearing the hook projections.

9. The engagement apparatus of claim 8 wherein the first and second sheets are constructed from the same material.

10. A engagement apparatus for selective engagement with an advancing web, the engagement apparatus comprising:
a base having an outer surface with hook-engaging structures disposed thereon;
a surface substrate sheet having first and second major surfaces, the second surface having desired characteristics for frictional engagement with an advancing web;

a plurality of hooking stems provided on and projecting from the first surface, the hooking stems including means for hooking the hook-engaging structures on the outer surface of the base to releasably affix the surface substrate sheet to the base.

11. The engagement apparatus of claim 10 wherein the outer surface of the base is cylindrical.

12. The engagement apparatus of claim 11 wherein the hook-engaging structures disposed on the exposed surface of the base are formed from a loop structure material and wherein the loop structure material is helically wrapped around the cylindrical exposed surface of the base.

13. The engagement apparatus of claim 11 wherein the surface substrate sheet is helically wrapped around the cylindrical outer surface of the base.

14. The engagement apparatus of claim 10 wherein the hook-engaging structures disposed on the outer surface of the base are formed from a loop structure material.

15. The engagement apparatus of claim 10 wherein the second surface of the surface substrate sheet has a plurality of surface stems projecting outwardly therefrom, the surface stems collectively defining an operative contact surface for the advancing web.

16. The engagement apparatus of claim 15 wherein the surface stems are generallyuniform in height.

17. The engagement apparatus of claim 16 wherein the surface stems are selected from the group consisting of thermoplastic polyurethanes, polyvinyl chlorides, polyamides, polyimides, polyolefins, polyesters, polystyrenes, nylons, acetals, block polyrners, polycarbonates, thermoplastic elastomers, and copolymers and combinations thereof.

18. The engagement apparatus of claim 15 wherein the surface stems directly adjoin and are integral with the second surface of the surface substrate sheet.

19. The engagement apparatus of claim 15 wherein the surface stems are generallyuniform in shape.

20. The engagement apparatus of claim 15 wherein the surface stems are uniformlydisposed across the second surface of the surface substrate sheet.

21. The engagement apparatus of claim 10 wherein the second surface of the surface substrate sheet includes an exterior layer selected from the group consisting of teflon substrates, polymeric coatings, polymeric coatings containing additives, coated abrasives, nonwoven abrasives, bristles, stems, brushes, smooth or textured polymeric films, glass coatings, cloth, rubber, paper, foam, nonwoven materials, and metal foils.

22. The engagement apparatus of claim 10 wherein the second surface of the surface substrate sheet is resistive to dye transfer from the advancing web in engagement therewith.

23. The engagement apparatus of claim 10 wherein the surface substrate sheet comprises a laminated composite including a first composite sheet having its outer side defining the first major surface and a second composite sheet having its outer side defining the second major surface, with inner sides of the two composite sheets being bonded together.

24. A low profile engagement apparatus for use on a roll having a cylindrical outer surface which traverses an advancing web, the engagement apparatus comprising:

a surface substrate sheet having first and second sides, the second side having desired characteristics for frictional engagement with an advancing web; and a repositionable pressure sensitive adhesive disposed on the first side of the surface substrate sheet to allow releasable adherence of the surface substrate sheet to the cylindrical outer surface of the roll for replacement or realignment the repositionable pressure sensitive adhesive being a low-tack adhesive that retains sufficient tack to be re-adhered once repositioned on the outer surface of the roll and that leaves no appreciable residue once removed therefrom.

25. The engagement apparatus of claim 24 wherein the second side of the surface substrate sheet has a plurality of surface stems projecting outwardly therefrom, the surface stems being disposed in a selected arrangement on and formed integrally with the surface substrate sheet, and the surface stems being generally uniform in height and collectively defining an operative web contact surface.

26. The engagement apparatus of claim 25 wherein the selected arrangement is a uniform array.

27. The engagement apparatus of claim 25 wherein the surface stems are selected from the group consisting of thermoplastic polyurethanes, polyvinyl chlorides, polyamides, polyimides, polyolefins, polyesters, polystyrenes, nylons, acetals, block polymers, polycarbonates, thermoplastic elastomers, and copolymers and combinations thereof.

28. The engagement apparatus of claim 25 wherein the surface stems are uniformlyshaped.

29. The engagement apparatus of claim 24 wherein the second side of the surface substrate sheet includes an exterior layer selected from the group consisting of teflon substrates, polymeric coatings, polymeric coatings containing additives, coated abrasives, nonwoven abrasives, bristles, brushes, smooth or textured polymeric films, glass coatings, cloth, rubber, paper, foam, nonwoven materials, and metal foils.

30. The engagement apparatus of claim 24 wherein the surface substrate sheet is helically wrapped around the cylindrical outer surface of the pull roll.

31. A method of making a textile pull roll with the engagement apparatus of claim 2, comprising the steps of:
providing a base having an outer cylindrical surface;
providing an inner sheet having first and second major surfaces, the second major surface being defined by a loop structure material;
bonding the first major surface of the inner sheet to the outer cylindrical surface;
providing a substrate sheet having first and second major surfaces, the second major surface of the outer sheet defining an engaging surface for contacting a textile web, and the first major surface of the outer sheet including means for hooking the loop structure material; and releasably affixing the means for hooking on the first major surface of the substrate sheet to the loop structure material of the second major surface of the inner sheet.

32. The method of claim 31 wherein the substrate sheet is an initial substrate sheet, and further comprising:
providing an alternative substrate sheet having first and second major surfaces, the first major surface of the alternative substrate sheet including means for hooking the loop structure material, and the second major surface of the alternative substrate sheet having an exterior surface that defines an alternative textile engaging surface for contacting the textile web;
separating the means for hooking on the first major surface of the initial substrate sheet from the loop structure material bonded to the base; and releasably affixing the means for hooking on the first major surface of the alternative substrate sheet to the loop structure material of the second major surface of the inner sheet.

33. A method of making a roll with the engagement apparatus of claim 1, comprising the steps of:
providing a base having an outer cylindrical surface;
providing a substrate sheet having first and second major sides;
releasably securing the first side of the substrate sheet to the outer cylindrical surface of the base; and providing a plurality of surface stems projecting outwardly from the second side of the substrate sheet, with the surface stems being disposed in a selected arrangement on and formed integrally with the substrate sheet, and the surface stems being generally uniform in height and collectively defining an operative workpiece contact surface for the roll.

34. The method of claim 33 wherein the substrate sheet is an initial substrate sheet, and further comprising:
providing an alternative substrate sheet having first and second major sides, the second side of the alternative substrate sheet having an exterior surface that defines an alternative operative workpiece contact surface;
separating the first side of the initial substrate sheet from the outer cylindrical surface of the base; and releasably bonding the first side of the alternative substrate sheet to the outer cylindrical surface of the base.

35. A method of making a roll with the apparatus of claim 24, comprising the steps of:
providing a base having an outer cylindrical surface;
providing a substrate sheet having first and second major sides, the second sidehaving desired characteristics for frictional engagement with an advancing web; and releasably bonding the first side of the substrate sheet to the outer cylindrical surface of the base with a repositionable pressure sensitive adhesive to permit ready removal or realignment of the substrate sheet relative to the base.

36. The method of claim 35 wherein the bonding step includes helically wrapping the substrate sheet around the outer cylindrical surface of the base.

37. The method of claim 35 wherein the substrate sheet is an initial substrate sheet, and further comprising:
providing an alternative substrate sheet having first and second major sides, the second side of the alternative substrate sheet having an exterior surface that defines an alternative engaging surface for contacting an advancing web;
separating the first side of the initial substrate sheet from the outer cylindrical surface of the base; and releasably bonding the first side of the alternative substrate sheet to the outer cylindrical surface of the base with a repositionable pressure sensitive adhesive to permit ready removal or realignment of the alternative substrate sheet.

38. The method of claim 37 wherein the desired frictional characteristics on thesecond side of the alternative substrate sheet are the same as the desired frictional characteristics on the second side of the initial substrate sheet.

39. The method of claim 37 wherein the desired fictional characteristics on the second side of the alternative substrate sheet are different from the desired frictional characteristics on the second side of the initial substrate sheet.

40. The method of claim 35, and further comprising:
positioning the repositionable pressure sensitive adhesive on the first side of the substrate sheet prior to the bonding step.

41. The method of claim 35, and further comprising:
providing a plurality of surface stems projecting outwardly from the second sideof the substrate sheet, the surface stems being disposed in a selected arrangement on and formed integrally with the substrate sheet, and the surface stems being generally uniform in height and collectively defining an operative contact surface for contacting an advancing web.

uniform array.

42. The engagement apparatus of claim 40 wherein the surface stems are selected from the group consisting of thermoplastic, polyvinyl chlorides, polyamides, polyolefins, polyesters, polystyrenes, nylons, acetals, block polymers, polycarbonates, thermoplastic elastomers, and copolymers and combinations thereof:

43. The engagement apparatus of claim 40 wherein the surface stems are uniformlyshaped.

44. The engagement apparatus of claim 39 wherein the second side of the surface substrate sheet includes an exterior layer selected from the group consisting of teflon substrates. polymeric coatings, polymeric coatings containing additives, coated abrasives, nonwoven abrasives, bristles, brushes, smooth or textured polymeric films, glass coatings, cloth, rubber, paper, foam, nonwoven materials, and metal foils.

45. The engagement apparatus of claim 39 wherein the surface substrate sheet is helically wrapped around the cylindrical outer surface of the pull roll.

46. The engagement apparatus of claim 39 wherein the repositionable pressure sensitive adhesive is carried on the first side of the surface substrate sheet.

47. A method of making a roll, comprising the steps of providing a base having an outer cylindrical surface;
providing a substrate sheet having first and second major sides, the second sidehaving desired characteristics for frictional engagement with an advancing web; and releasably bonding the first side of substrate sheet to the outer cylindrical surface of the base with a repositionable pressure sensitive adhesive to permit ready removal or realignment of the substrate sheet relative to the base.

48. The method of claim 47 wherein the bonding step includes helically wrapping the substrate sheet around the outer cylindrical surface of the base.

49. The method of claim 47 wherein the substrate sheet is an initial substrate sheet, and further comprising:

providing an alternative substrate sheet having first and second major sides, the second side of the alternative substrate sheet having an exterior surface that defines an alternative engaging surface for contacting an advancing web;
separating the first side of the initial substrate sheet from the outer cylindrical surface of the base; and releasably bonding the first side of the alternative substrate sheet to the outer cylindrical surface of the base with a repositionable pressure sensitive adhesive to permit ready removal or realignment of the alternative substrate sheet

50 The method of claim 49 wherein the desired frictional characteristics on the second side of the alternative substrate sheet are the same as the desired frictional characteristics on the second side of the initial substrate sheet.

51 The method of claim 49 wherein the desired frictional characteristics on the second side of the alternative substrate sheet are different from the desired frictional characteristics on the second side of the initial substrate sheet.

52. The method of claim 47, and further comprising:
positioning the repositionable pressure sensitive adhesive on the first side of the substrate sheet prior to the bonding step

53 The method of claim 47, and further comprising:
providing a plurality of surface stems projecting outwardly from the second sideof the substrate sheet, the surface stems being disposed in a selected arrangement on and formed integrally with the substrate sheet, and the surface stems being generally uniform in height and collectively defining an operative contact surface for contacting an advancing web.

54. The method of claim 47 wherein the selected arrangement is a uniform array.

55. A method of changing the outer textile engaging surface of a textile pull roll comprising:
providing a pull roll having a cylindrical pull base with an initial substrate sheet releasably affixed to the pull roll base, the initial substrate sheet having first and second major sides, with the second side of the initial substrate sheet being defined by a textile engagement material and the first side thereof being bonded to the pull roll base by a repositionable pressure sensitive adhesive;
removing the initial substrate sheet and textile engagement material thereon from the pull roll base:
providing a replacement substrate sheet having first and second major sides, with its second side being defined by a replacement textile engagement material; and affixing the replacement substrate sheet to the cylindrical pull roll base by means of a repositionable pressure sensitive adhesive disposed therebetween to permit replacement or realignment thereof on the cylindrical pull roll base.

56. The method of claim 55 wherein each substrate sheet bears the repositionablepressure sensitive adhesive for the bonding thereof to the outer cylindrical surface of the base.